Hymenoptera
' Hymenoptera' is a large of s, comprising the , s, s, and s. Over 150,000 living species of Hymenoptera have been described, in addition to over 2,000 extinct ones. Females typically have a special for inserting eggs into hosts or places that are otherwise inaccessible. The ovipositor is often modified into a . The young develop through (complete )—that is, they have a worm-like larval stage and an inactive pupal stage before they mature. The Apocrita contains a large number of families. Some traditional taxa such as the (containing many families of s) have been found on molecular analysis to be . ism evolved once, and it is found today across most Apocritan families, though it has been secondarily lost several times. The gives a condensed overview of the phylogeny, illustrated with major groups. The tree is not fully resolved. Phylogenetic tree |colour=red |cladogram= ( -present) |barbegin1=red |2= |bar1=red |2= |bar1=red |label2= |2= (stem sawflies) |bar1=red |2= (horntails or wood wasps) |bar1=red |2= (wood wasps) |bar1=red |label2=''parasitism'' |2= ( wood wasps) |barend1=red |label2= "wasp waist" 200mya |2= ( s, s, s) }} }} }} }} }} }} }} }} }} }} Apocrita The Apocrita are a of s in the order . It includes s, s, and s, and consists of many families. It contains the most advanced hymenopterans and is distinguished from by the narrow "waist" ( ) formed between the first two segments of the actual ; the first abdominal segment is fused to the thorax, and is called the . Therefore, it is general practice, when discussing the body of an apocritan in a technical sense, to refer to the and (or "gaster") rather than the "thorax" and "abdomen", respectively. The evolution of a constricted waist was an important adaption for the lifestyle of the ancestral apocritan, allowing more maneuverability of the female's . The either extends freely or is retracted, and may be developed into a stinger for both defense and paralyzing prey. Larvae are legless and blind, and either feed inside a host (plant or animal) or in a nest cell provisioned by their mothers. , the giant honeybee, from family on '' in Hyderabad, India}} The Apocrita have historically been split into two groups, " " and , but these are rankless groupings in present classifications, if they appear at all. The term Parasitica is an artificial ( ) group comprising the majority of hymenopteran insects, with respective members living as on what amounts to nearly half of all insects, and many noninsects. Most species are small, with the ovipositor adapted for piercing. In some hosts, the parasitoids induce prematurely, and in others it is prolonged. There are even species that are s, parasitoids on other parasitoids. The Parasitica lay their s inside or on another insect (egg, larva or pupa) and their larvae grow and develop within or on that host. The host is nearly always killed. Many are used as agents to control pests, such as s, , , and s. The Aculeata are a group that includes those species in which the female's is modified into a to inject . Groups include the familiar ants, bees, and various types of parasitic and predatory wasps; it also includes all of the hymenopterans. Among the nonparasitic and nonsocial Aculeata, larvae are fed with captured prey (typically alive and paralyzed) or may be fed pollen and nectar. The Aculeata feed their young prey ( s and s), or and (bees), or perhaps seeds, , or nonviable eggs (ants). Phylogenetic tree |1= |label2='' ism'' |sublabel2=''evolved once '' |2= (parasitoid wood wasps) |label2='Apocrita' |sublabel2= wasp waist '' |2= |2= |2= |2= plus |2= |3= }} |3=''other superfamilies }} |label2= |sublabel2=''stinging'' |2= (jewel wasps) |2= (wasps, hornets) |2= (velvet ants) |2= (spider wasps) |3=''other families'' }} |2= |2= (ants) |label2= |2= |2= |2= (aphid wasps) |2= }} |2= (bees) }} }} }} }} }} }} }} }} }} }} }} }} }} }} }} }} References Category:Tree of life